<script>
  import simplePoll from '../../../lib/utils/simple_poll';
  import eventHub from '../../event_hub';
  import statusIcon from '../mr_widget_status_icon.vue';
  import Flash from '../../../flash';

  export default {
    name: 'MRWidgetRebase',
    components: {
      statusIcon,
    },
    props: {
      mr: {
        type: Object,
        required: true,
      },
      service: {
        type: Object,
        required: true,
      },
    },
    data() {
      return {
        isMakingRequest: false,
        rebasingError: null,
      };
    },
    computed: {
      status() {
        if (this.mr.rebaseInProgress || this.isMakingRequest) {
          return 'loading';
        }
        if (!this.mr.canPushToSourceBranch && !this.mr.rebaseInProgress) {
          return 'warning';
        }
        return 'success';
      },
      showDisabledButton() {
        return ['failed', 'loading'].includes(this.status);
      },
    },
    methods: {
      rebase() {
        this.isMakingRequest = true;
        this.rebasingError = null;

        this.service.rebase()
          .then(() => {
            simplePoll(this.checkRebaseStatus);
          })
          .catch((error) => {
            this.rebasingError = error.merge_error;
            this.isMakingRequest = false;
            Flash('Something went wrong. Please try again.');
          });
      },
      checkRebaseStatus(continuePolling, stopPolling) {
        this.service.poll()
          .then(res => res.data)
          .then((res) => {
            if (res.rebase_in_progress) {
              continuePolling();
            } else {
              this.isMakingRequest = false;

              if (res.merge_error && res.merge_error.length) {
                this.rebasingError = res.merge_error;
                Flash('Something went wrong. Please try again.');
              }

              eventHub.$emit('MRWidgetUpdateRequested');
              stopPolling();
            }
          })
          .catch(() => {
            this.isMakingRequest = false;
            Flash('Something went wrong. Please try again.');
            stopPolling();
          });
      },
    },
  };
</script>
<template>
  <div class="mr-widget-body media">
    <status-icon
      :status="status"
      :show-disabled-button="showDisabledButton"
    />

    <div class="rebase-state-find-class-convention media media-body space-children">
      <template v-if="mr.rebaseInProgress || isMakingRequest">
        <span class="bold">
          Rebase in progress
        </span>
      </template>
      <template v-if="!mr.rebaseInProgress && !mr.canPushToSourceBranch">
        <span class="bold">
          Fast-forward merge is not possible.
          Rebase the source branch onto
          <span class="label-branch">{{ mr.targetBranch }}</span>
          to allow this merge request to be merged.
        </span>
      </template>
      <template v-if="!mr.rebaseInProgress && mr.canPushToSourceBranch && !isMakingRequest">
        <div
          class="accept-merge-holder clearfix
js-toggle-container accept-action media space-children"
        >
          <button
            :disabled="isMakingRequest"
            type="button"
            class="btn btn-sm btn-reopen btn-success qa-mr-rebase-button"
            @click="rebase"
          >
            <gl-loading-icon v-if="isMakingRequest" />
            Rebase
          </button>
          <span
            v-if="!rebasingError"
            class="bold"
          >
            Fast-forward merge is not possible.
            Rebase the source branch onto the target branch or merge target
            branch into source branch to allow this merge request to be merged.
          </span>
          <span
            v-else
            class="bold danger">
            {{ rebasingError }}
          </span>
        </div>
      </template>
    </div>
  </div>
</template>
